Surgical stapling device with firing lockout mechanism

ABSTRACT

A surgical stapling device includes a tool assembly and a drive assembly for actuating the tool assembly. The tool assembly includes a cartridge assembly having a staple cartridge and an anvil assembly that supports a lockout mechanism. The staple cartridge includes a cartridge body and an actuation sled and knife assembly that includes an actuation sled and a knife. The actuation sled and knife assembly is movable in relation to the cartridge body to eject staples from the cartridge body and to cut tissue. The anvil assembly supports a lockout mechanism that includes a lockout member that is movable between a locked position and an unlocked position. The drive assembly is movable from a retracted position to an advanced position to move the actuation sled and knife assembly from its retracted position to its advanced position. In the locked position, the lockout member obstructs movement of the drive assembly from its retracted position towards its advanced position.

FIELD

The disclosure is directed to surgical stapling devices having staple cartridges and, more particularly, to surgical stapling devices with lockout mechanisms to prevent firing of the stapling device when a knife is not present in the staple cartridge.

BACKGROUND

Surgical stapling devices for simultaneously stapling and cutting tissue are well known in the art and include a tool assembly and a drive assembly. The tool assembly includes an anvil assembly and a cartridge assembly having a channel member and a staple cartridge that is received within the channel member. Typically, the staple cartridge includes a cartridge body that supports staples, pushers, and an actuation sled. The actuation sled is movable through the cartridge body from a retracted position to an advanced position into sequential engagement with the pushers to sequentially eject the staples from the cartridge body.

In some stapling devices, a knife is supported on the actuation sled and is movable with the actuation sled through the cartridge body. The drive assembly is positioned proximally of the actuation sled and is movable in relation to the anvil and cartridge assemblies to advance the actuation sled and knife through the staple cartridge to move the tool assembly between open and clamped positions, to eject the staples from the cartridge body, and to cut tissue clamped between the anvil and cartridge assemblies. After the stapling device is fired, the actuation sled and knife remain in a distal portion of the staple cartridge.

When a stapling device is fired with a staple cartridge that does not have an actuation sled and/or a knife present in a proximal portion of the staple cartridge, staples will not be ejected from the staple cartridge and tissue will not be cut. A continuing need exists for a lock mechanism of simple construction that can prevent advancement of a drive assembly of a stapling device through the staple cartridge when a sled and/or knife is not present in the proximal portion of the staple cartridge.

SUMMARY

This disclosure is directed to a stapling device having a tool assembly including a cartridge assembly, an anvil assembly, and a drive assembly. The anvil assembly supports a lockout mechanism that prevents advancement of the drive assembly when the cartridge assembly does not have an actuation sled or knife present in a proximal portion of the cartridge assembly.

Aspects of this disclosure are directed to a surgical stapling device that includes an elongate body, a tool assembly, and a drive assembly. The elongate body has a proximal portion and a distal portion. The tool assembly is supported on the distal portion of the elongate body and includes a cartridge assembly and an anvil assembly that are coupled together to facilitate movement of the tool assembly between open and clamped positions. The cartridge assembly includes a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly. The actuation sled and knife assembly includes an actuation sled and a knife supported on the actuation sled for movement between raised and lowered positions. The actuation sled and knife assembly is movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies. The anvil assembly includes a lockout mechanism that is linearly movable from a locked position to an unlocked position. The actuation sled and knife assembly is positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position. The drive assembly is positioned proximally of the actuation sled and knife assembly and is movable in relation to the tool assembly between a retracted position and an advanced position to move the tool assembly between the open and clamped positions and to move the actuation sled and knife assembly from its retracted position to its advanced position. The lockout mechanism is positioned to prevent movement of the drive assembly from its retracted position to its advanced position when the lockout mechanism is in its locked position.

In aspects of the disclosure, the lockout mechanism includes a lockout member that is movable between the locked and unlocked positions.

In some aspects of the disclosure, the lockout mechanism includes a biasing member that is positioned to urge the lockout member to the locked position.

In certain aspects of the disclosure, the anvil assembly includes an anvil plate that supports a housing that defines an opening, and the lockout member and the biasing member are positioned within the housing.

In aspects of the disclosure, the lockout member is movable through the opening in the housing between the locked and unlocked positions.

In some aspects of the disclosure, the anvil assembly includes an anvil plate that defines a central knife slot that defines a longitudinal axis, and the lockout member extending across at least a portion of the central knife slot when the lockout member is in the locked position.

In certain aspects of the disclosure, the drive assembly includes a working member that has an I-beam configuration and includes a first beam, a second beam, and a vertical strut that connects the first beam to the second beam.

In aspects of the disclosure, the vertical strut is positioned to translate through the central knife slot of the anvil plate as the drive assembly moves between its retracted and advanced positions.

In some aspects of the disclosure, the lockout member has a distally facing cam surface that defines a plane that forms an acute angle with the longitudinal axis of the central knife slot of the anvil plate.

In certain aspects of the disclosure, the distally facing cam surface engages the vertical strut of the drive assembly as the drive assembly is moved from the advanced position to its retracted position to move the lockout member from the locked position to the unlocked position.

In aspects of the disclosure, the lockout member includes a proximally facing stop surface that defines a plane that is substantially perpendicular to the longitudinal axis of the central knife slot of the anvil plate.

In some aspects of the disclosure, the knife of the actuation sled and knife assembly is positioned to engage the lockout member when the actuation sled and knife assembly is in a retracted position to retain the lockout member in the unlocked position.

Other aspects of the disclosure are directed to a tool assembly that includes a cartridge assembly, an anvil assembly, and a lockout mechanism. The cartridge assembly includes a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly. The actuation sled and knife assembly includes an actuation sled and a knife that is supported on the actuation sled for movement between raised and lowered positions. The actuation sled and knife assembly is movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies. The anvil assembly is coupled to the cartridge assembly to facilitate movement of the tool assembly between open and clamped positions. The lockout mechanism is supported on the anvil assembly and is linearly movable from a locked position to an unlocked position. The actuation sled and knife assembly is positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position.

Still other aspects of the disclosure are directed to a tool assembly that includes a cartridge assembly, an anvil assembly, and a lockout mechanism. The cartridge assembly includes a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly. The actuation sled and knife assembly includes an actuation sled and a knife. The actuation sled and knife assembly is movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies. The anvil assembly is coupled to the cartridge assembly to facilitate movement of the tool assembly between open and clamped positions. The lockout mechanism is supported on the anvil assembly and is linearly movable from a locked position to an unlocked position. The actuation sled and knife assembly is positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position.

Other features of the disclosure will be appreciated from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the disclosure are described herein below with reference to the drawings, wherein:

FIG. 1 is side perspective view of a stapling device according to aspects of the disclosure including a tool assembly in an open position;

FIG. 2 is a side perspective view of the tool assembly of the stapling device shown in FIG. 1 with a staple cartridge separated from a channel member of a cartridge assembly of the tool assembly;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG. 2 illustrating a proximal portion of the cartridge assembly;

FIG. 4 is a side perspective view of an actuation sled and knife assembly of the staple cartridge shown in FIG. 2 ;

FIG. 5 is an exploded view of the staple cartridge of the cartridge assembly shown in FIG. 2 ;

FIG. 5A is a side perspective, exploded view of the actuation sled and knife assembly of the staple cartridge shown in FIG. 5 ;

FIG. 6 is a side perspective view of an anvil assembly of the tool assembly shown in FIG. 2 ;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG. 6 illustrating a lockout mechanism;

FIG. 8 is a side perspective view of a lockout member of the lockout mechanism shown in FIG. 7 ;

FIG. 9 is a top perspective view of the lockout member of the lockout mechanism shown in FIG. 7 ;

FIG. 10 is a top view of a proximal portion of the anvil assembly shown in FIG. 6 ;

FIG. 11 is an enlarged view of the indicated area of detail shown in FIG. 10 ;

FIG. 12 is a perspective view from a first side of a distal portion of a drive assembly of the stapling device shown in FIG. 1 ;

FIG. 13 is a perspective view from a second side of the distal portion of the drive assembly shown in FIG. 12 ;

FIG. 14 is an enlarged view of the indicated area of detail shown in FIG. 2 ;

FIG. 15 is a side perspective of the proximal portion of the tool assembly of the stapling device shown in FIG. 1 with the anvil assembly and the cartridge assembly shown in phantom as a working member of the drive assembly is advanced from a retracted position to a position to move the tool assembly to the clamped position;

FIG. 16 is a schematic view illustrating the positions of the lockout mechanism, the working member of the drive assembly, and knife of the actuation sled and knife assembly prior to engagement of the knife with the lockout mechanism;

FIG. 17 is a side perspective view of the working member of the drive assembly and the actuation sled and knife assembly as the drive assembly lifts the knife of the actuation sled and knife assembly from a lowered position to a raised position;

FIG. 18 is a schematic view illustrating the positions of the lockout mechanism, the working member of the drive assembly, and knife of the actuation sled and knife assembly with the knife engaged with the lockout mechanism to move the lockout mechanism from a locked position to an unlocked position;

FIG. 19 is a top view of a proximal portion of the anvil assembly and the drive assembly as the drive assembly returns to its retracted position after the stapling device has been fired with the lockout mechanism retained in the unlocked position by the drive assembly; and

FIG. 20 is a top view of the proximal portion of the anvil assembly and the distal portion of the drive assembly shown in phantom with the drive assembly in its retracted position and the lockout mechanism in the locked position.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that aspects of the disclosure are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure.

In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician during use of the stapling device in its customary manner, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician during use of the stapling device in its customary manner. In addition, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel. Further, directional terms such as front, rear, upper, lower, top, bottom, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

The disclosed surgical stapling device includes a tool assembly and a drive assembly for actuating the tool assembly. The tool assembly includes a cartridge assembly having a staple cartridge and an anvil assembly that supports a lockout mechanism. The staple cartridge includes a cartridge body and an actuation sled and knife assembly that includes an actuation sled and a knife. The actuation sled and knife assembly is movable in relation to the cartridge body to eject staples from the cartridge body and to cut tissue. The anvil assembly supports a lockout mechanism that includes a lockout member that is linearly movable between a locked position and an unlocked position. The drive assembly is movable from a retracted position to an advanced position to move the actuation sled and knife assembly from its retracted position to its advanced position. In the locked position, the lockout member obstructs movement of the drive assembly from its retracted position towards its advanced position.

FIG. 1 illustrates a surgical stapling device according to aspects of the disclosure shown generally as stapling device 10. The stapling device 10 includes a handle assembly 12, an elongate body 14, and a tool assembly 16. The elongate body 14 defines a longitudinal axis “X” (FIG. 1 ). The handle assembly 12 includes a body 18 that defines a hand grip 18 a, a plurality of actuator buttons 20, and a rotation knob 22. The rotation knob 22 is rotatably supported on a distal portion of the body 18 of the handle assembly 12 and supports the elongate body 14 to facilitate rotation of the elongate body 14 and the tool assembly 16 in relation to the handle assembly 12 about the longitudinal axis “X”. The actuator buttons 20 control operation of the various functions of the stapling device 10 including articulation, clamping, firing, and cutting of tissue.

The tool assembly 16 includes an anvil assembly 24 and a cartridge assembly 26 that are that are coupled together to facilitate movement of the tool assembly 16 between open and clamped positions. Although the stapling device 10 is illustrated as an electrically powered stapling device, it is envisioned that the disclosed tool assembly 16 would also be suitable for use with manually powered surgical stapling devices and robotically operated stapling systems. U.S. Pat. No. 9,055,943 discloses a surgical stapling device including a powered handle assembly, U.S. Pat. No. 6,241,139 discloses a surgical stapling device including a manually actuated handle assembly, and U.S. Pat. No. 9,962,159 discloses a stapling device that is configured for use with a robotic system.

FIGS. 2-5 illustrate the cartridge assembly 26 (FIG. 1 ) which includes a staple cartridge 28 and a channel member 30 that defines a recess 30 a that receives the staple cartridge 28. In aspects of the disclosure, the staple cartridge 28 is releasably supported within the recess 30 a of the channel member 30 and is replaceable to facilitate reuse of the stapling device 10.

The staple cartridge 28 includes a cartridge body 32, an actuation sled and knife assembly 34 (FIG. 4 ), pushers 36 (FIG. 5 ), staples 38 (FIG. 5 ), and a base plate 40. The cartridge body 32 defines a central knife slot 42 and staple receiving pockets 44. In aspects of the disclosure, the staple receiving pockets 44 are aligned in rows that are positioned on each side of the central knife slot 42. Although three rows of staple receiving pockets 44 are shown on each side of the central knife slot 42, it is envisioned that the cartridge body 32 may define one or more rows of staple receiving pockets 44 on each side of the central knife slot 42. Each of the staple receiving pockets 44 receives one of the staples 38 and one of the pushers 36. The pushers 36 support the staples 38 and are engaged by an actuation sled 34 a of the actuation sled and knife assembly 34 as the actuation sled and knife assembly 34 is advanced through the cartridge body 32 to eject the staples 38 from the cartridge body 32. The base plate 40 is secured to the bottom of the cartridge body 32 to prevent the pushers 36 and staples 38 from falling from the cartridge body 32 prior to firing of the stapling device 10 (FIG. 1 ).

FIGS. 4-5A illustrate the actuation sled and knife assembly 34 (FIG. 5A) which includes the actuation sled 34 a, a knife 66, and a biasing member 68 (FIG. 5A). The actuation sled 34 a supports the knife 66 and is movable within the cartridge body 32 (FIG. 5 ) from a retracted position to an advanced position. The actuation sled 34 a includes a body 50 (FIG. 5A) that has a central portion 52 and cam surfaces 54 that are positioned on opposite sides of the central portion 52 of the body 50. The cam surfaces 54 define ramps that are positioned to engage the pushers 36 as the actuation sled 34 a moves from its retracted position towards its advanced position to sequentially eject the staples 38 from the cartridge body 32.

The central portion 52 of the actuation sled 34 a supports the knife 66 and includes spaced walls 56 and a housing 58. Each of the spaced walls 56 defines a circular recess 60 (FIG. 5A). The housing 58 extends distally of and is positioned between longitudinal axes defined by the spaced walls 56. The housing 58 defines a recess 62 that is aligned with the central knife slot 42 of the cartridge body 32.

The knife 66 has a body 70 that has a Z-shaped configuration and includes an elongate arm 72, a first portion 74 that extends downwardly from a distal end of the elongate arm 72, and a second portion 76 that extends upwardly from a proximal end of the elongate arm 72. The first portion 74 of the body 70 of the knife 66 supports a pivot member 78 that is received within the circular recesses 60 in the spaced walls 56 of the actuation sled 34 a such that the knife 66 is pivotably supported on the actuation sled 34 a between raised and lowered positions. In the raised position of the knife 66, the first portion 74 of the body 70 of the knife 66 is received within the recess 62 of the housing 58 of the central portion 52 of the actuation sled 34 a. The second portion 76 of the body 70 of the knife 66 defines a distally facing cutting edge 80 that is shielded within the central knife slot 42 of the cartridge body 32 when the knife 66 is in the lowered position and extends above the central knife slot 42 when the knife 66 is in the raised position. The body 70 of the knife 66 also includes a protrusion 82 that extends laterally of the elongate arm 72. In aspects of the disclosure, the protrusion 82 is positioned on the proximal portion of the elongate arm 72 of the knife 66.

The biasing member 68 of the actuation sled and knife assembly 34 is received within the recess 62 of the housing 58 of the central portion 52 of the actuation sled 34 a and engages the first portion 74 of the body 70 of the knife 66 at a position above an axis defined by the pivot member 78 of the knife 66 to urge the knife 66 towards the lowered position. In aspects of the disclosure, the biasing member 68 includes a coil spring although it is envisioned that other types of biasing mechanisms or members could be used in place of the coil spring.

FIGS. 6 and 7 illustrate the anvil assembly 24 which includes an anvil cover 90 and an anvil plate 92. The anvil cover 90 includes a mounting portion 94, and a cover portion 96 (FIG. 15 ) that extends distally from the mounting portion 94 along the anvil plate 92. The mounting portion 94 includes spaced extensions 98 that define bores 100 and extend downwardly from the anvil plate 92 towards the channel 30 of the cartridge assembly 26. The anvil plate 92 includes a tissue engaging surface 102 that is in juxtaposed relation to the staple cartridge 28 when the tool assembly 16 is in a clamped position (FIG. 1 ). The tissue engaging surface 102 defines a plurality of staple deforming recesses 104. The distal edge of the spaced extensions 98 define tissue stops 98 a that are positioned slightly distal of the proximal-most staple deforming recesses 104. The anvil plate 92 has a side opposite to the tissue engaging surface 102 that defines an elongated recess 91(FIG. 16 ). The anvil cover 90 is secured to the anvil plate 92, e.g., by welding or crimping, such that the cover portion 96 (FIG. 15 ) of the anvil cover 90 encloses the elongated recess 91 of the anvil plate 92 to define a channel 93 (FIG. 16 ) within the anvil assembly 24. The anvil plate 92 also defines a central knife slot 108 that extends through the tissue engaging surface 102 of the anvil plate 92 and communicates with the elongated recess (not shown) of the anvil plate 92.

The bores 100 in the extensions 98 of the anvil cover 90 receive pivot members 112 (FIG. 2 ) that extend through the bores 100 into bores (not shown) defined in a proximal portion of the channel member 30 (FIG. 2 ) to pivotably secure the anvil assembly 24 to the cartridge assembly 26. In aspects of the disclosure, the cartridge assembly 26 can pivot towards the anvil assembly 24 between the open and clamped positions. It is envisioned that the tool assembly 16 (FIG. 2 ) could also be configured to pivot toward the cartridge assembly 26.

The anvil assembly 24 includes a lockout mechanism 114 (FIG. 7 ) illustrated in FIGS. 6-11 that is supported on the anvil plate 92 between the extensions 98 of the mounting portion 94 of the anvil assembly 24 proximally of the tissue engaging surface 102 of the anvil plate 92. In aspects of the disclosure, the lockout mechanism 114 is supported on an outer surface 102 a of the anvil plate 92 that is contiguous with the tissue engaging surface 102 of the anvil plate 92. The lockout mechanism 114 includes a lockout member 116 and a biasing member 118. The lockout member 116 is received within a housing 120 secured to the surface 102 a of the anvil plate 92 and defines a cavity 122. In aspects of the disclosure, the housing 120 has a rectangular configuration and defines an opening 124 (FIG. 7 ) that faces the central knife slot 108.

The lockout member 116 includes a body 125 that has a first end portion that is received within the cavity 122 of the housing 120 supported on the anvil plate 92 of the anvil assembly 24 and a second end portion that extends transversely through the opening 124 of the housing 120 towards the central knife slot 108 of the anvil assembly 24. The first end portion of the body 125 of the lockout member 116 supports wings 128 that extend distally and proximally from the body 125. The wings 128 extend from the body 125 within the cavity 122 defined by the housing 120 to prevent the lockout member 116 from passing entirely through the opening 124. In a locked position of the lockout mechanism 114, the wings 128 engage an inner wall 120 a (FIG. 11 ) of the housing 120 that defines the opening 124. The second end portion of the body 125 of the lockout member 116 includes a distally facing cam surface 126 and a proximally facing stop surface 127. The distally facing cam surface 126 defines a plane that forms an acute angle with a longitudinal axis defined by the central knife slot 108 of the anvil plate 92. The proximally facing stop surface 127 defines a plane that is substantially perpendicular to the longitudinal axis of the central knife slot 108 of the anvil plate 92.

The biasing member 118 of the lockout mechanism 114 is positioned within the cavity 122 of the housing 120 to urge the lockout member 116 from an unlocked position spaced outwardly of the central knife slot 108 of the anvil assembly 24 towards a locked position. In the locked position, the lockout member 116 extends at least partially across the central knife slot 108 of the anvil assembly 24 to obstruct advancement of the drive assembly 130. In aspects of the disclosure, the biasing member 118 is secured to a post 129 supported on the anvil assembly 24 within the cavity 122 of the housing 120 such that the biasing member 118 is positioned in compression between the post 129 and the lockout member 116. In some aspects of the disclosure, the lockout member 116 defines a bore 129 a (FIG. 8 ) that receives one end of the biasing member 118. In aspects of the disclosure, the biasing member 118 includes a coil spring although the use of other types of biasing members is envisioned.

FIGS. 12 and 13 illustrate a drive assembly 130 of the stapling device 10 (FIG. 1 ) which includes a resilient and/or flexible drive beam 132 and a working member 134. The resilient drive beam 132 has a proximal portion (not shown) that is coupled to a drive rod (not shown) supported within the elongate body 14 of the stapling device 10 (FIG. 1 ) and a distal portion that is coupled to the working member 134. In aspects of the disclosure, the resilient drive beam 132 is formed from laminated sheets of material, e.g., steel, that are welded to the working member 134. Alternately other materials of construction and securement techniques are envisioned.

The working member 134 of the drive assembly 130 has an I-beam configuration and includes a first beam 138, a second beam 140, and a vertical strut 142 that connects the first beam 138 to the second beam 140. The vertical strut 142 defines a cutout 142 a (FIG. 13 ) that is positioned beneath the first beam 138 and receives the second portion 76 (FIG. 4 ) of the knife 66 when the knife 66 is moved to its raised position. The working member 134 is positioned proximally of the actuation sled 34 a (FIG. 12 ) and is movable through the tool assembly 16 between retracted and advanced positions to move the actuation sled and knife assembly 34 through the tool assembly 16 (FIG. 1 ) from its retracted position to its advanced position. As the working member 134 moves through the cartridge assembly 26, the first beam 138 is received within the channel 93 (FIG. 16 ) defined within the anvil assembly 24 (FIG. 6 ), the second beam 140 is engaged with the cartridge assembly 26, and the vertical strut 142 moves through the central knife slots 42 (FIGS. 3 ) and 108 (FIG. 6 ) of the cartridge body 32 and the anvil plate 92, respectively.

The vertical strut 142 defines a cam channel 152. The cam channel 152 (FIG. 13 ) is angled upwardly and proximally from a central portion of the vertical strut 142 and is positioned to receive the protrusion 82 of the knife 66 (FIG. 4 ) when the drive assembly 130 is moved from its retracted position towards its advanced position to move the knife 66 from its lowered position to its raised position.

FIG. 14 illustrates the drive assembly 130 in its retracted position. When the drive assembly 130 is in its retracted position, the tool assembly 16 is in the open position with the cartridge assembly 26 pivoted away from the anvil assembly 24, and the working member 134 of the drive assembly 130 is aligned with the anvil assembly 24. The actuation sled and drive assembly 34 is supported in the cartridge assembly 26 and is misaligned with the drive assembly 130. In the retracted position of the drive assembly 130, the lockout member 116 of the lockout mechanism 114 extends at least partially across the central knife slot 108 (FIG. 6 ) of the anvil assembly 24 and is positioned within the cutout 142 a of the vertical strut 142.

FIGS. 15 and 16 illustrate the proximal portion of the tool assembly 16 as the drive assembly 130 is advanced from its retracted position towards a clamped position in the direction of arrow “A”. As the working member 134 of the drive assembly 130 is advanced towards its clamped position, the working member 134 moves into engagement with the tool assembly 16 to move the tool assembly 16 from the open position (FIG. 1 ) to the clamped position. In the clamped position of the drive assembly 130, the vertical strut 142 of the working member 134 of the drive assembly 130 is still spaced from the central portion of the actuation sled 34 a of the actuation sled and knife assembly 34 such that the actuation sled and knife assembly 34 remains in its retracted position. The lockout member 116 of the lockout mechanism 114 also remains in the locked position and extends at least partially across the central knife slot 108 (FIG. 6 ) of the anvil assembly 24 into the cutout 142 a of the vertical strut 142.

FIGS. 16 and 17 . 16 illustrate a schematic view of the drive assembly 130 and the actuation sled and knife assembly 34 as the drive assembly 130 advances from the clamped position to move the knife 66 from the lowered position (FIG. 15 ) to the raised position (FIG. 17 ). When the drive assembly 130 moves from its clamped position towards its advanced position, the protrusion 82 (FIG. 4 ) on the knife 66 is received in the cam channel 152 (FIG. 13 ) in the vertical strut 142 of the drive assembly 130. As the drive assembly 130 continues to advance, the protrusion 82 of the knife 66 moves upwardly through the cam channel 152 to pivot the knife 66 about the pivot member 78 (FIG. 4 ) in the direction of arrow “B” in FIG. 17 from the lowered position to the raised position. When the knife 66 is in the raised position, the vertical strut 142 of the working member 134 of the drive assembly 130 is positioned in abutting relation to the central portion 52 of the actuation sled 34 a such that further advancement of the drive assembly 130 advances the actuation sled and knife assembly 34 through the cartridge body 32 (FIG. 5 ) of the staple cartridge 28.

FIG. 18 illustrates the interaction between the knife 66 and the lockout mechanism 114 as the knife 66 moves from the lowered position to the raised position. When the knife 66 is moved in the direction of arrow “C” in FIG. 18 from the lowered position to the raised position, the second portion 76 (FIG. 17 ) of the body 70 of the knife 66 engages the distally facing cam surface 126 of the lockout member 116 to urge the lockout member 116 in the direction of arrow “D” against the urging of the biasing member 118 from the locked position extending at least partially across the central knife slot 108 of the anvil assembly 24 further into the housing 120 of the lockout mechanism 114 to the unlocked position. When the lockout member 116 of the lockout mechanism 114 is moved to the unlocked position upon movement of the knife 66 to the raised position, the drive assembly 130 is free to move from its clamped position to its advanced position to advance the actuation sled and knife assembly 34 through the cartridge body 32 (FIG. 5 ) to eject the staples 38 from the staple cartridge 28 (FIG. 5 ) and to cut tissue clamped between the anvil assembly 24 and the cartridge assembly 26. It is noted that the lockout member 116 is retained in the unlocked position as the drive assembly 130 moves through the cartridge body 32 of the staple cartridge 28 via engagement with the flexible drive beam 132 of the drive assembly 130.

FIGS. 19 and 20 illustrate the drive assembly and the anvil assembly 24 as the drive assembly 130 is moved from its advanced position back to its retracted position. When the drive assembly 130 moves from its advanced position back to its retracted position in the direction of arrows “E” in FIG. 19 , the actuation sled and knife assembly 34 remains in its advanced position and the flexible drive beam 132 engages the lockout member 116 of the lockout mechanism 114 to retain the lockout member 116 in the unlocked position. When the working member 134 moves proximally past the lockout member 116 of the lockout mechanism 114, the lockout member 116 is moved by the biasing member 118 back to the locked position. In the locked position, the lockout member 116 moves back into the cutout 142 a of the vertical strut 142 of the working member 134 of the drive assembly 130 such that the proximally facing stop surface 127 is positioned at least partially across the central knife slot 108 of the anvil assembly 24 to prevent readvancement of the drive assembly 130.

In some aspects of the disclosure, depending on the configuration of the drive assembly, the distally facing cam surface 126 of the lockout member 116 may be positioned to engage the vertical strut 142 of the drive assembly 130 as the drive assembly is moved from the advanced position to its retracted position to move the lockout member 116 from the locked position to the unlocked position.

When the staple cartridge 28 does not include an actuation sled and knife assembly 34 or a knife 66, the lockout member 116 cannot be moved from the locked position (FIG. 20 ) to the unlocked position as described above. As such, the stapling device 10 (FIG. 1 ) cannot be fired. The disclosed lockout mechanism 114 prevents refiring of the stapling 10 (FIG. 1 ) with a spent staple cartridge 28 (FIG. 5 ) and also prevents firing of a stapling device 10 that includes a staple cartridge that does not have a knife present.

Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 

1. A surgical stapling device comprising: an elongate body having a proximal portion and a distal portion; a tool assembly supported on the distal portion of the elongate body, the tool assembly including a cartridge assembly and an anvil assembly that are coupled together to facilitate movement of the tool assembly between open and clamped positions, the cartridge assembly including a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly, the actuation sled and knife assembly including an actuation sled and a knife supported on the actuation sled, the knife movable between raised and lowered positions, the actuation sled and knife assembly movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies, the anvil assembly including a lockout mechanism that is linearly movable from a locked position to an unlocked position, the actuation sled and knife assembly being positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position; and a drive assembly positioned proximally of the actuation sled and knife assembly, the drive assembly movable in relation to the tool assembly between a retracted position and an advanced position to move the tool assembly between the open and clamped positions and to move the actuation sled and knife assembly from its retracted position to its advanced position, wherein the lockout mechanism is positioned to prevent movement of the drive assembly from its retracted position to its advanced position when the lockout mechanism is in its locked position.
 2. The surgical stapling device of claim 1, wherein the lockout mechanism includes a lockout member that is movable between the locked and unlocked positions.
 3. The surgical stapling device of claim 2, wherein the lockout mechanism includes a biasing member that is positioned to urge the lockout member to the locked position.
 4. The surgical stapling device of claim 3, wherein the anvil assembly includes an anvil plate that supports a housing that defines an opening, the lockout member and the biasing member positioned within the housing.
 5. The surgical stapling device of claim 4, wherein the lockout member is movable through the opening in the housing between the locked and unlocked positions.
 6. The surgical stapling device of claim 2, wherein the anvil assembly includes an anvil plate that defines a central knife slot that defines a longitudinal axis, and the lockout member extending across at least a portion of the central knife slot when the lockout member is in the locked position.
 7. The surgical stapling device of claim 6, wherein the drive assembly includes a working member having an I-beam configuration, the working member having a first beam, a second beam, and a vertical strut that connects the first beam to the second beam, the vertical strut positioned to translate through the central knife slot of the anvil plate as the drive assembly moves between its retracted and advanced positions.
 8. The surgical stapling device of claim 7, wherein the lockout member has a distally facing cam surface that defines a plane, the plane defining an acute angle with the longitudinal axis of the central knife slot of the anvil plate, the distally facing cam surface engaging the vertical strut of the drive assembly as the drive assembly is moved from the advanced position to its retracted position to move the lockout member from the locked position to the unlocked position.
 9. The surgical stapling device of claim 2, wherein the lockout member includes a proximally facing stop surface that defines a plane that is substantially perpendicular to the longitudinal axis of the central knife slot of the anvil plate.
 10. The surgical stapling device of claim 9, wherein knife of the actuation sled and knife assembly is positioned to engage the lockout member when the actuation sled and knife assembly is in a retracted position to retain the lockout member in the unlocked position.
 11. A tool assembly comprising: a cartridge assembly including a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly, the actuation sled and knife assembly including an actuation sled and a knife supported on the actuation sled, the knife movable between raised and lowered positions, the actuation sled and knife assembly movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies; an anvil assembly coupled to the cartridge assembly to facilitate movement of the tool assembly between open and clamped positions; and a lockout mechanism supported on the anvil assembly, the lockout member being linearly movable from a locked position to an unlocked position, the actuation sled and knife assembly being positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position.
 12. The tool assembly of claim 11, wherein the lockout mechanism includes a lockout member that is movable between the locked and unlocked positions.
 13. The tool assembly of claim 12, wherein the lockout mechanism includes a biasing member that is positioned to urge the lockout member to the locked position.
 14. The tool assembly of claim 13, wherein the anvil assembly includes an anvil plate that supports a housing that defines an opening, the lockout member and the biasing member positioned within the housing.
 15. The tool assembly of claim 14, wherein the lockout member is movable through the opening in the housing between the locked and unlocked positions.
 16. The tool assembly of claim 12, wherein the anvil assembly includes an anvil plate that defines a central knife slot that defines a longitudinal axis, and the lockout member extending across at least a portion of the central knife slot when the lockout member is in the locked position.
 17. The tool assembly of claim 16, wherein the lockout member has a distally facing cam surface that defines a plane, the plane defining an acute angle with the longitudinal axis of the central knife slot of the anvil plate.
 18. The tool assembly of claim 17, wherein the lockout member includes a proximally facing stop surface that defines a plane that is substantially perpendicular to the longitudinal axis of the central knife slot of the anvil plate.
 19. The tool assembly of claim 18, wherein knife of the actuation sled and knife assembly is positioned to engage the lockout member when the actuation sled and knife assembly is in a retracted position to retain the lockout member in the unlocked position.
 20. A tool assembly comprising: a cartridge assembly including a staple cartridge having a cartridge body, staples, pushers, and an actuation sled and knife assembly, the actuation sled and knife assembly including an actuation sled and a knife, the actuation sled and knife assembly movable within the cartridge body from a retracted position to an advanced position to eject the staples from the cartridge body and to cut tissue clamped between the cartridge and anvil assemblies; an anvil assembly coupled to the cartridge assembly to facilitate movement of the tool assembly between open and clamped positions; and a lockout mechanism supported on the anvil assembly at a longitudinally fixed position, the lockout member being linearly movable from a locked position to an unlocked position, the actuation sled and knife assembly being positioned to urge the lockout mechanism to its unlocked position when the actuation sled and knife assembly is in its retracted position. 